Lithium batteries which use lithium as the negative electrode active material have lately attracted attention as high energy density batteries, and much active research has been conducted.
As a solvent of the nonaqueous electrolyte for these types of batteries, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, sulfolane, 1,2-dimethoxydiethane, tetrahydrofuran and dioxolane and the like can be used alone or in the form of a mixture of two or three of these substances. As a solute dissolved in the solvent there can be mentioned LiPF.sub.6, LiBF.sub.4, LiClO.sub.4, LiCF.sub.3 SO.sub.3, LiAsF.sub.6, LiN (CF.sub.3 SO.sub.2).sub.2, LiCF.sub.3 (CF.sub.2).sub.3 SO.sub.3 or the like.
It is a problem that an organic solvent and a negative electrode having lithium as an active material react chemically in nonaqueous electrolyte consisting of a solute and, as a solvent, dioxolane alone or a two or three component solvent including dioxolane and reduce battery capacity after storage. Therefore, it is very important to inhibit self-discharge during storage to put this kind of battery to practical use.
Japanese patent publication (Laid-Open) Sho 60-91565 discloses a battery having improved properties and which uses a nonaqueous electrolyte including dioxolane as a solvent. However, it is a problem when dioxolane is used as solvent that a negative electrode in which lithium is an active material reacts chemically with the dioxolane, and reduces battery capacity after storage.
Japanese patent publication (Laid-Open) Sho 49-108525 discloses that pyridine is added to an electrolyte to improve storage properties. However, even if pyridine is added to an electrolyte, sufficient improvement is not obtained in a battery in which an organic solvent containing dioxolane is used. Further improvement is required.